Silane compound containing perfluoro(poly)ether group

ABSTRACT

wherein the symbols are as defined herein.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Rule 53(b) Continuation of U.S. application Ser.No. 15/748,986 filed Jan. 30, 2018, which is a National Stage ofInternational Application No. PCT/JP2016/070721 filed Jul. 13, 2016,claiming priority based on Japanese Patent Application No. 2015-152468filed Jul. 31, 2015, Japanese Patent Application No. 2015-181146 filedSep. 14, 2015 and Japanese Patent Application No. 2015-215019 filed Oct.30, 2015, the contents of all of which are incorporated herein byreference in their entirety.

TECHNICAL FIELD

The present invention relates to a perfluoro(poly)ether group containingsilane compound.

BACKGROUND ART

A certain fluorine-containing silane compound is known to be able toprovide excellent water-repellency, oil-repellency, antifoulingproperty, or the like when it is used in a surface treatment of a basematerial. A layer (hereinafter, referred to as a “surface-treatinglayer”) formed from a surface-treating agent comprising afluorine-containing silane compound is applied to various base materialssuch as a glass, a plastic, a fiber and a building material as aso-called functional thin film.

As such fluorine-containing compound, a perfluoropolyether groupcontaining silane compound which has a perfluoropolyether group in itsmain molecular chain and a hydrolyzable group bonding to a Si atom inits molecular terminal or terminal portion is known (Patent Documents 1and 2).

PRIOR ART DOCUMENT Patent Document

-   Patent Document 1: JP 2008-534696 A-   Patent Document 2: International Publication No. 97/07155

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

The surface-treating layer is requested for high durability to provide abase material with a desired function for a long time. The layer formedfrom the surface-treating agent containing the perfluoropolyether groupcontaining silane compound has been suitably used in an optical membersuch as glasses, a touch panel or the like which is required to havelight permeability or transparency since it can exert the abovefunctions even in form of a thin film. In particular, in theseapplications, the friction durability is required to be furtherimproved.

However, a layer formed from a surface-treating agent containing aconventional perfluoropolyether group containing silane compounddescribed above is no longer necessarily enough to meet the increasingdemand to improve the friction durability.

An object of the present invention is to provide a perfluoro(poly)ethergroup containing silane compound which is able to form a layer havingwater-repellency, oil-repellency and antifouling property as well ashigh friction durability.

Means to Solve the Problem

As a result of intensively studying, the inventors of the presentinvention have found that use of a perfluoropolyether group containingsilane compound having a plurality of Si atom having a hydrolyzablegroup improves friction durability, and the inventors reach the presentinvention.

According to the first aspect of the present invention, there isprovided a perfluoro(poly)ether group containing silane compound offormula (1a) or formula (1b):

(Rf-PFPE)_(β)-X—(CR^(a) _(k)R^(b) _(l)R^(c) _(m))_(α)  (1a)

(R^(c) _(m)R^(b) _(l)R^(a) _(k)C)_(α)—X-PFPE-X—(CR^(a) _(k)R^(b)_(l)R^(c) _(m))_(α)  (1b)

wherein:

Rf is each independently at each occurrence an alkyl group having 1-16carbon atoms which may be substituted by one or more fluorine atoms;

PFPE is each independently at each occurrence a group of the formula:

—(OC₄F₈)_(α)—(OC₃F₆)_(b)—(OC₂F₄)_(c)—(OCF₂)_(d)—

-   -   wherein a, b, c and d are each independently an integer of        0-200, the sum of a, b, c and d is 1 or more, and the occurrence        order of the respective repeating units in parentheses with the        subscript a, b, c or d is not limited in the formula;

X is each independently a single bond or a 2-10 valent organic group;

α is each independently an integer of 1-9;

β is an integer of 1-9;

R^(a) is each independently at each occurrence —Z—CR¹ _(p)R² _(q)R³_(r);

Z is each independently at each occurrence an oxygen atom or a divalentorganic group;

R¹ is each independently at each occurrence R^(a′);

R^(a′) has the same definition as that of R^(a);

in R^(a), the number of C atoms which are straightly linked via the Zgroup is up to five;

R² is each independently at each occurrence —Y—SiR⁵ _(n)R⁶ _(3-n);

Y is each independently at each occurrence an oxygen atom or a divalentorganic group;

R⁵ is each independently at each occurrence a hydroxyl group or ahydrolyzable group;

R⁶ is each independently at each occurrence a hydrogen atom or a loweralkyl group;

n is an integer of 1-3 independently per unit —Y—SiR⁵ _(n)R⁶ _(3-n);

R³ is each independently at each occurrence a hydrogen atom or a loweralkyl group;

p is each independently at each occurrence an integer of 0-3;

q is each independently at each occurrence an integer of 0-3;

r is each independently at each occurrence an integer of 0-3;

R^(b) is each independently at each occurrence —Y—SiR⁵ _(n)R⁶ _(3-n);

R^(c) is each independently at each occurrence a hydrogen atom or alower alkyl group;

k is each independently at each occurrence an integer of 0-3;

l is each independently at each occurrence an integer of 0-3; and

m is each independently at each occurrence an integer of 0-3;

with the proviso that in the formula at least one q is 2 or 3, or atleast one l is 2 or 3.

According to the second aspect of the present invention, there isprovided a surface-treating agent comprising the perfluoro(poly)ethergroup containing silane compound described above.

According to the third aspect of the present invention, there isprovided a pellet comprising the surface-treating agent described above.

According to the fourth aspect of the present invention, there isprovided an article comprising a base material and a layer which isformed on a surface of the base material from the perfluoro(poly)ethergroup containing silane compound described above or the surface-treatingagent described above.

Effect of the Invention

According to the present invention, there is provided a novelperfluoro(poly)ether group containing silane compound. Furthermore,there is provided a surface treating agent obtained by using theperfluoro(poly)ether group containing silane compound. By using them,the surface-treating layer having water-repellency, oil-repellency andantifouling property as well as excellent friction durability can beformed.

EMBODIMENTS TO CARRY OUT THE INVENTION

Hereinafter, the compound of the present invention will be described.

A “hydrocarbon group” as used herein represents a group containing acarbon atom and a hydrogen atom which is obtained by removing a hydrogenatom from a hydrocarbon. Examples of the hydrocarbon group include, butare not particularly limited to, a hydrocarbon group having 1-20 carbonatoms which may be substituted with one or more substituents, forexample, an aliphatic hydrocarbon group, an aromatic hydrocarbon group,and the like. The “aliphatic hydrocarbon group” may be straight,branched or cyclic, and may be saturated or unsaturated. The hydrocarbongroup may contain one or more ring structures. It is noted that thehydrocarbon group may have one or more N, O, S, Si, amide, sulfonyl,siloxane, carbonyl, carbonyloxy, or the like at its end or in itsmolecular chain.

As used herein, examples of the substituent of the “hydrocarbon group”include, but are not particularly limited to, for example a halogenatom; and a C₁₋₆ alkyl group, a C₂₋₆ alkenyl group, a C₂₋₆ alkynylgroup, a C₃₋₁₀ cycloalkyl group, a C₃₋₁₀ unsaturated cycloalkyl group, a5-10 membered heterocyclyl group, a 5-10 membered unsaturatedheterocyclyl group, a C₆₋₁₀ aryl group, a 5-10 membered heteroarylgroup, and the like, which may be substituted by one or more halogenatoms.

As used herein, an “organic group” represents a group containing acarbon atom. A “2-10 valent organic group” represents a 2-10 valentgroup containing a carbon atom. Examples of the 2-10 valent organicgroup include, but are not particularly limited to, a 2-10 valent groupobtained by removing 1-9 hydrogen atoms from a hydrocarbon group. Forexample, examples of the divalent organic group include, but are notparticularly limited to, a divalent group obtained by removing onehydrogen atom from a hydrocarbon group from a hydrocarbon group.

The present invention provides a perfluoro(poly)ether group(hereinafter, also referred to as “PFPE”) containing silane compound ofthe formula (1a) or the formula (1b) (hereinafter, also referred to as“a PFPE containing silane compound of the present invention”).

(Rf-PFPE)_(β)-X—(CR^(a) _(k)R^(b) _(l)R^(c) _(m))_(α)  (1a)

(R^(c) _(m)R^(b) _(l)R^(a) _(k)C)_(α)—X-PFPE-X—(CR^(a) _(k)R^(b)_(l)R^(c) _(m))_(α)  (1b)

In the formula, Rf is an alkyl group having 1-16 carbon atoms which maybe substituted by one or more fluorine atoms.

The “alkyl group having 1-16 carbon atoms” in the alkyl having 1-16carbon atoms which may be substituted by one or more fluorine atoms maybe straight or branched, and preferably is a straight or branched alkylgroup having 1-6 carbon atoms, in particular 1-3 carbon atoms, morepreferably a straight alkyl group having 1-3 carbon atoms.

Rf is preferably an alkyl having 1-16 carbon atoms substituted by one ormore fluorine atoms, more preferably a CF₂H—C₁₋₁₅ fluoroalkylene group,more preferably a perfluoroalkyl group having 1-16 carbon atoms.

The perfluoroalkyl group having 1-16 carbon atoms may be straight orbranched, and preferably is a straight or branched perfluoroalkyl grouphaving 1-6 carbon atoms, in particular 1-3 carbon atoms, more preferablya straight perfluoroalkyl group having 1-3 carbon atoms, specifically—CF₃, —CF₂CF₃ or —CF₂CF₂CF₃.

In the formula described above, PFPE is—(OC₄F₈)_(a)—(OC₃F₆)_(b)—(OC₂F₄)_(c)—(OCF₂)_(d)—, and corresponds to aperfluoro(poly)ether group. Herein, a, b, c and d are each independently0 or an integer of 1 or more. The sum of a, b, c and d is 1 or more.Preferably, a, b, c and d are each independently an integer of 0 or moreand 200 or less, for example an integer of 1 or more and 200 or less,more preferably each independently an integer of 0 or more and 100 orless, for example an integer of 1-200. The sum of a, b, c and d ispreferably 5 or more, more preferably 10 or more, for example 10 or moreand 100 or less. The occurrence order of the respective repeating unitsin parentheses with the subscript a, b, c or d is not limited in theformula. Among these repeating units, the —(OC₄F₈)— group may be any of—(OCF₂CF₂CF₂CF₂)—, —(OCF(CF₃)CF₂CF₂)—, —(OCF₂CF(CF₃)CF₂)—,—(OCF₂CF₂CF(CF₃))—, —(OC(CF₃)₂CF₂)—, —(OCF₂C(CF₃)₂)—,—(OCF(CF₃)CF(CF₃))—, —(OCF(C₂F₅)CF₂)— and —(OCF₂CF(C₂F₅))—, preferably—(OCF₂CF₂CF₂CF₂)—. The —(OC₃F₆)— group may be any of —(OCF₂CF₂CF₂)—,—(OCF(CF₃)CF₂)— and —(OCF₂CF(CF₃))—, preferably —(OCF₂CF₂CF₂)—. The—(OC₂F₄)— group may be any of —(OCF₂CF₂)— and —(OCF(CF₃))—, preferably—(OCF₂CF₂)—.

In one embodiment, PFPE is —(OC₃F₆)_(b)— wherein b is an integer of 1 ormore and 200 or less, preferably 5 or more and 200 or less, morepreferably 10 or more and 200 or less, preferably —(OCF₂CF₂CF₂)_(b)—wherein b is an integer of 1 or more and 200 or less, preferably 5 ormore and 200 or less, more preferably 10 or more and 200 or less, or—(OCF(CF₃)CF₂)_(b)— wherein b is an integer of 1 or more and 200 orless, preferably 5 or more and 200 or less, more preferably 10 or moreand 200 or less, more preferably —(OCF₂CF₂CF₂)_(b)— wherein b is aninteger of 1 or more and 200 or less, preferably 5 or more and 200 orless, more preferably 10 or more and 200 or less.

In another embodiment, PFPE is—(OC₄F₈)_(a)—(OC₃F₆)_(b)—(OC₂F₄)—(OCF₂)_(d)— wherein a and b are eachindependently an integer of 0 or more and 30 or less, c and d are eachindependently an integer of 1 or more and 200 or less, preferably 5 ormore and 200 or less, more preferably 10 or more and 200 or less, andthe occurrence order of the respective repeating units in parentheseswith the subscript a, b, c or d is not limited in the formula;preferably—(OCF₂CF₂CF₂CF₂)_(a)—(OCF₂CF₂CF₂)_(b)—(OCF₂CF₂)_(c)—(OCF₂)_(d)—. In oneembodiment, PFPE may be —(OC₂F₄), —(OCF₂)_(d)— wherein c and d are eachindependently an integer of 1 or more and 200 or less, preferably 5 ormore and 200 or less, more preferably 10 or more and 200 or less, andthe occurrence order of the respective repeating units in parentheseswith the subscript c or d is not limited in the formula.

In one embodiment, In—(OC₄F₈)_(a)—(OC₃F₆)_(b)—(OC₂F₄)_(c)—(OCF₂)_(d)—described above, a lower limit of a ratio of c to d (hereinafter,referred to as an “c/d ratio”) may be 0.2, preferably 0.3, and an upperlimit of the c/d ratio may be 1.5, preferably 1.3, more preferably 1.1,further preferably 0.9. By setting the c/d ratio to less than 1.5, slipproperty and friction durability of the surface-treating layer formedfrom the compound are more increased. The lower the c/d ratio, thehigher the slip property and the higher the friction durability of thesurface-treating layer becomes. Additionally, by setting the c/d ratioto 0.2 or more, stability of the compound can be more increased. Thehigher the c/d ratio, the higher the stability of the compound becomes.

In further another embodiment, PFPE is a group of —(OC₂F₄—R⁸)_(n″)—. Inthe formula, R⁸ is a group selected from OC₂F₄, OC₃F₆ and OC₄F₈, or acombination of 2 or 3 groups independently selected from these groups.Examples of the combination of 2 or 3 groups independently selected fromOC₂F₄, OC₃F₆ and OC₄F₈ include, but not limited to, for example,—OC₂F₄OC₃F₆—, —OC₂F₄OC₄F₈—, —OC₃F₆OC₂F₄—, —OC₃F₆OC₃F₆—, —OC₃F₆OC₄F₈—,—OC₄F₈OC₄F₈—, —OC₄F₈OC₃F₆—, —OC₄F₈OC₂F₄—, —OC₂F₄OC₂F₄OC₃F₆—,—OC₂F₄OC₂F₄OC₄F₈—, —OC₂F₄OC₃F₆OC₂F₄—, —OC₂F₄OC₃F₆OC₃F₆—,—OC₂F₄OC₄F₈OC₂F₄—, —OC₃F₆OC₂F₄OC₂F₄—, —OC₃F₆OC₂F₄OC₃F₆—,—OC₃F₆OC₃F₆OC₂F₄—, —OC₄F₈OC₂F₄OC₂F₄—, and the like. n″ is an integer of2-100, preferably an integer of 2-50. In the above-mentioned formula,OC₂F₄, OC₃F₆ and OC₄F₈ may be straight or branched, preferably straight.In this embodiment, PFPE is preferably —(OC₂F₄—OC₃F₆)_(n″)— or—(OC₂F₄—OC₄F₈)_(f)—.

In the formula, X is each independently a single bond or a 2-10 valentorganic group. X is recognized to be a linker which connects between aperfluoropolyether moiety (i.e., an Rf-PFPE moiety or -PFPE- moiety)providing mainly water-repellency, surface slip property and the likeand a moiety (i.e., a group in parentheses with the subscript α)providing an ability to bind to a base material in the compound of theformula (1a) and (1b). Therefore, X may be any organic group as long asthe compound of the formula (1a) and (1b) can stably exist.

In the formula, α is an integer of 1-9, and β is an integer of 1-9. αand β may be varied depending on the valence number of the X group. Inthe formula (1a), the sum of α and β is the valence number of X. Forexample, when X is a 10 valent organic group, the sum of a and β is 10,for example, α is 9 and β is 1, α is 5 and R is 5, or α is 1 and β is 9.When X is a divalent organic group, α and β are 1. In the formula (1b),α is a value obtained by subtracting 1 from the valence number of X.

X is preferably a 2-7 valent, more preferably 2-4 valent, morepreferably a divalent organic group.

In one embodiment, X is a 2-4 valent organic group, α is 1-3, and β is1.

In another embodiment, X is a divalent organic group, α is 1, and βis 1. In this case, the formulae (1a) and (1b) are represented by thefollowing formulae (1a′) and (1b′).

Rf-PFPE-X—CR^(a) _(k)R^(b) _(l)R^(c) _(m)  (1a)

R^(c) _(m)R^(b) _(l)R^(a) _(k)C—X-PFPE-X—CR^(a) _(k)R^(b) _(l)R^(c)_(m)  (1b)

Examples of X include, but are not particularly limited to, for examplea divalent group of the following formula:

—(R³¹)_(p′)—(X^(a))_(q′)—

wherein:

R³¹ is each independently a single bond, —(CH₂)_(s′)— or an o-, m- orp-phenylene group, preferably —(CH₂)_(s′)—,

s′ is an integer of 1-20, preferably an integer of 1-6, more preferablyan integer of 1-3, further more preferably 1 or 2,

X^(a) is —(X_(b))_(1′)—,

X^(b) is each independently at each occurrence a group selected from thegroup consisting of —O—, —S—, an o-, m- or p-phenylene group, —C(O)O—,—Si(R³³)₂—, —(Si(R³³)₂₀)_(m′)—Si(R³³)₂—, —CONR³⁴—, —O—CONR³⁴—, —NR³⁴—and —(CH₂)_(n′)—,

R³³ is each independently at each occurrence a phenyl group, a C₁₋₆alkyl group or a C₁₋₆ alkoxy group, preferably a phenyl group or a C₁₋₆alkyl group, more preferably a methyl group,

R³⁴ is each independently at each occurrence a hydrogen atom, a phenylgroup or a C₁₋₆ alkyl group (preferably a methyl group),

m′ is each independently at each occurrence an integer of 1-100,preferably an integer of 1-20,

n′ is each independently at each occurrence an integer of 1-20,preferably an integer of 1-6, more preferably an integer of 1-3,

l′ is an integer of 1-10, preferably an integer of 1-5, more preferablyan integer of 1-3,

p′ is 0 or 1,

q′ is 0 or 1, and

at least one of p′ and q′ is 1, and the occurrence order of therespective repeating units in parentheses with the subscript p′ or q′ isnot limited in the formula. Here, R³¹ and X^(a) (typically, a hydrogenatom in R³¹ and X^(a)) may be substituted with one or more substituentsselected from a fluorine atom, a C₁₋₃ alkyl group and a C₁₋₃ fluoroalkylgroup.

Preferably, X is

a C₁-20 alkylene group,R³¹—X^(c)—R³¹— or—X^(d)—R³¹—wherein R³¹ is as defined above.

More preferably, X is

an C₁-20 alkylene group,—(CH₂)_(s′)—X^(c)—,—(CH₂)_(s′)—X^(c)—(CH₂)_(t′)—

—X^(d)—, or

—X^(d)—(CH₂)_(t′)—wherein s′ and t′ are as defined above.

In the formula, X is

—O—, —S—, —C(O)O—, —CONR³⁴—, —O—CONR³⁴—,

—Si(R³³)₂—,—(Si(R³³)₂O)_(m′)—Si(R³³)₂—,—O—(CH₂)_(u′)—(Si(R³³)₂O)_(m′)—Si(R³³)₂—,—O—(CH₂)_(u′)—Si(R³³)₂—O—Si(R³³)₂—CH₂CH₂—Si(R³³)₂—O—Si(R³³)₂—,—O—(CH₂)_(u′)—Si(OCH₃)₂OSi(OCH₃)₂—,—CONR³⁴—(CH₂)_(u′)—(Si(R³³)₂O)_(m′)—Si(R³³)₂—,—CONR³⁴—(CH₂)_(u′)—N(R³⁴)—, or—CONR³⁴-(o-, m- or p-phenylene)-Si(R³³)₂—wherein R³³, R³⁴ and m′ are as defined above, and

u′ is an integer of 1-20, preferably an integer of 2-6, more preferablyan integer of 2-3. X^(c) is preferably —O—.

In the formula, X^(d) is

—S—, —C(O)O—, —CONR³⁴—

—CONR³⁴—(CH₂)_(u′)—(Si(R³³)₂O)_(m′)—Si(R³³)₂—,—CONR³⁴—(CH₂)_(u′)—N(R³⁴)—, or—CONR³⁴-(o-, m- or p-phenylene)-Si(R³)₂—wherein each of symbols is as defined above.

More preferably, X is

an C₁₋₂₀ alkylene group,—(CH₂)_(s′)—X^(c)—(CH₂)_(t′)—, or—X^(d)—(CH₂)_(t′)—wherein each of symbols is as defined above.

Furthermore preferably, X is

an C₁₋₂₀ alkylene group,—(CH₂)_(s′)—O—(CH₂)_(t′)—,—(CH₂)_(s′)—(Si(R³³)₂O)_(m′)—Si(R³³)₂—(CH₂)_(t′)—,—(CH₂)_(s′)—O—(CH₂)_(u′)—(Si(R³³)₂O)_(m′)—Si(R³³)₂—(CH₂)_(t′)—, or—(CH₂)_(s′)—O—(CH₂)_(t′)—Si(R³³)₂—(CH₂)_(u′)—Si(R³³)₂—(C_(v)H_(2v))—wherein R³³, m′, s′, t′ and u′ are as defined above, and v is an integerof 1-20, preferably an integer of 2-6, more preferably an integer of2-3.

In the formula, —(C_(v)H_(2v))— may be straight or branched, forexample, may be, for example, —CH₂CH₂—, —CH₂CH₂CH₂—, —CH(CH₃)—,—CH(CH₃)CH₂—.

X may be substituted with one or more substituents selected from afluorine atom, a C₁₋₃ alkyl group and a C₁₋₃ fluoroalkyl group(preferably, a C₁₋₃ perfluoroalkyl group).

In another embodiment, examples of X include, for example, the followinggroups:

wherein R⁴¹ is each independently a hydrogen atom, a phenyl group, analkyl group having 1-6 carbon atoms, or a C₁₋₆ alkoxy group, preferablya methyl group;

D is a group selected from:

—CH₂O(CH₂)₂—,—CH₂O(CH₂)₃—,—CF₂O(CH₂)₃—,—(CH₂)₂—,—(CH₂)₃—,—(CH₂)₄—,—CONH—(CH₂)₃—,—CON(CH₃)—(CH₂)₃—,—CON(Ph)-(CH₂)₃— (wherein Ph is a phenyl group), and

wherein R⁴² is each independently a hydrogen atom, a C₁₋₆ alkyl group,or a C₁₋₆ alkoxy group, preferably a methyl group or a methoxy group,more preferably a methyl group,

E is —(CH₂)_(n)— wherein n is an integer of 2-6, and

D binds to PFPE of the main backbone, and E binds to a group opposite toPFPE.

Specific examples of X include, for example:

—CH₂O(CH₂)₂—,—CH₂O(CH₂)₃—,—CH₂O(CH₂)₆—,—CH₂O(CH₂)₃Si(CH₃)₂OSi(CH₃)₂(CH₂)₂—,—CH₂O(CH₂)₃Si(CH₃)₂OSi(CH₃)₂OSi(CH₃)₂(CH₂)₂—,—CH₂O(CH₂)₃Si(CH₃)₂O(Si(CH₃)₂O)₂Si(CH₃)₂(CH₂)₂—,—CH₂O(CH₂)₃Si(CH₃)₂O(Si(CH₃)₂O)₃Si(CH₃)₂(CH₂)₂—,—CH₂O(CH₂)₃Si(CH₃)₂O(Si(CH₃)₂O)₁₀Si(CH₃)₂(CH₂)₂—,—CH₂O(CH₂)₃Si(CH₃)₂O(Si(CH₃)₂O)₂OSi(CH₃)₂(CH₂)₂—,—CH₂OCF₂CHFOCF₂—,—CH₂OCF₂CHFOCF₂CF₂—,—CH₂OCF₂CHFOCF₂CF₂CF₂—,—CH₂OCH₂CF₂CF₂OCF₂—,—CH₂OCH₂CF₂CF₂OCF₂CF₂—,—CH₂OCH₂CF₂CF₂OCF₂CF₂CF₂—,—CH₂OCH₂CF₂CF₂OCF(CF₃)CF₂OCF₂—,—CH₂OCH₂CF₂CF₂OCF(CF₃)CF₂OCF₂CF₂—,—CH₂OCH₂CF₂CF₂OCF(CF₃)CF₂OCF₂CF₂CF₂—,—CH₂OCH₂CHFCF₂OCF₂—,—CH₂OCH₂CHFCF₂OCF₂CF₂—,—CH₂OCH₂CHFCF₂OCF₂CF₂CF₂—,—CH₂OCH₂CHFCF₂OCF(CF₃)CF₂OCF₂—,—CH₂OCH₂CHFCF₂OCF(CF₃)CF₂OCF₂CF₂—,—CH₂OCH₂CHFCF₂OCF(CF₃)CF₂OCF₂CF₂CF₂——CH₂OCH₂(CH₂)₇CH₂Si(OCH₃)₂OSi(OCH₃)₂(CH₂)₂Si(OCH₃)₂OSi(OCH₃)₂(CH₂)₂—,—CH₂OCH₂CH₂CH₂Si(OCH₃)₂OSi(OCH₃)₂(CH₂)₃—,—(CH₂)₂—,—(CH₂)₃—,—(CH₂)₄—,—(CH₂)₅—,—(CH₂)₆—,—CONH—(CH₂)₃—,—CON(CH₃)—(CH₂)₃—,—CON(Ph)-(CH₂)₃— (wherein Ph is phenyl),—CONH—(CH₂)₆—,—CON(CH₃)—(CH₂)₆—,—CON(Ph)-(CH₂)₆— (wherein Ph is phenyl),—CONH—(CH₂)₂NH(CH₂)₃—,—CONH—(CH₂)₆NH(CH₂)₃—,—CH₂O—CONH—(CH₂)₃—,—CH₂O—CONH—(CH₂)₆—,—S—(CH₂)₃—,—(CH₂)₂S(CH₂)₃—,—CONH—(CH₂)₃Si(CH₃)₂OSi(CH₃)₂(CH₂)₂—,—CONH—(CH₂)₃Si(CH₃)₂OSi(CH₃)₂OSi(CH₃)₂(CH₂)₂—,—CONH—(CH₂)₃Si(CH₃)₂O(Si(CH₃)₂O)₂Si(CH₃)₂(CH₂)₂—,—CONH—(CH₂)₃Si(CH₃)₂O(Si(CH₃)₂O)₃Si(CH₃)₂(CH₂)₂—,—CONH—(CH₂)₃Si(CH₃)₂O(Si(CH₃)₂O)₁₀Si(CH₃)₂(CH₂)₂—,—CONH—(CH₂)₃Si(CH₃)₂O(Si(CH₃)₂O)₂OSi(CH₃)₂(CH₂)₂——C(O)O—(CH₂)₃—,—C(O)O—(CH₂)₆—,—CH₂—O—(CH₂)₃—Si(CH₃)₂—(CH₂)₂—Si(CH₃)₂—(CH₂)₂—,—CH₂—O—(CH₂)₃—Si(CH₃)₂—(CH₂)₂—Si(CH₃)₂—CH(CH₃)—,—CH₂—O—(CH₂)₃—Si(CH₃)₂—(CH₂)₂—Si(CH₃)₂—(CH₂)₃—,—CH₂—O—(CH₂)₃—Si(CH₃)₂—(CH₂)₂—Si(CH₃)₂—CH(CH₃)—CH₂—,

—OCH₂—,

—O(CH₂)₃—,

—OCFHCF₂—,

In another embodiment, X is each independently a 3-10 valent organicgroup.

In this embodiment, examples of X include the following groups:

wherein R⁴¹ is each independently a hydrogen atom, a phenyl group, analkyl group having 1-6 carbon atoms, or a C₁₋₆ alkoxy group, preferablya methyl group;

in each X¹, some of T are a following group which binds to PFPE of themain backbone of the formula (1a) and (1b):

—CH₂O(CH₂)₂—,—CH₂O(CH₂)₃—,—CF₂O(CH₂)₃—,—(CH₂)₂—,—(CH₂)₃—,—(CH₂)₄—,—CONH—(CH₂)₃—,—CON(CH₃)—(CH₂)₃—,—CON(Ph)-(CH₂)₃— (wherein Ph is phenyl), or

wherein R⁴² is each independently a hydrogen atom, a C₁₋₆ alkyl group,or a C₁₋₆ alkoxy group, preferably a methyl group or a methoxy group,more preferably a methyl group,

some of the other T are —(CH₂)_(n″)— (wherein n″ is an integer of 2-6)attached to the group opposite to PFPE which is a molecular backbone(i.e., —CR^(a) _(k)R^(b) _(l)R^(c) _(m) in the formula (1a) and (1b)),and

the others T are each independently a methyl group, a phenyl group, or aC₁₋₆ alkoxy, if present.

In the formula, R^(a) is each independently at each occurrence —Z—CR¹_(p)R² _(q)R³ _(r).

In the formula, Z is each independently at each occurrence, an oxygenatom or a divalent organic group.

Z is preferably a C₁₋₆ alkylene group, —(CH₂)_(g)—O—(CH₂)_(h)— (whereing is an integer of 0-6, for example, an integer of 1-6, h is an integerof 0-6, for example, an integer of 1-6) or -phenylene-(CH₂)_(i)—(wherein i is an integer of 0-6), more preferably a C₁₋₃ alkylene group.These groups may be substituted with, for example, one or moresubstituents selected form a fluorine atom, a C₁₋₆ alkyl group, a C₂₋₆alkenyl group, and a C₂₋₆ alkynyl group.

In the formula, R¹ is each independently at each occurrence R^(a′).R^(a′) is as defined for R^(a).

In R^(a), the number of C atoms which are linearly connected via Z is upto five. That is, in R^(a), when there is at least one R¹, there are twoor more C atoms which are linearly connected via Z in R^(a). The numberof such C atoms which are linearly connected via Z is five at most. Itis noted that “the number of such C atoms which are linearly connectedvia Z in R^(a) is equal to the repeating number of —Z—C— which arelinearly connected in R^(a).

For example, one example in which C atoms are connected via Z in R^(a)is shown below.

In the above formula, * represents a position binding to C of the mainbackbone, and . . . represents that a predetermined group other than ZCbinds thereto, that is, when all three bonds of a C atom are . . . , itmeans an end point of the repeat of ZC. The number on the right shoulderof C means the number of occurrences of C which is linearly connectedvia the Z group from *. In other words, in the chain in which the repeatof ZC is completed at C², “the number of such C atoms which are linearlyconnected via the Z group in R^(a)” is 2. Similarly, in the chain inwhich the repeat of ZC is completed at C³, C⁴ and C⁵, respectively, “thenumber of such C atoms which are linearly connected via the Z group inR^(a)” is 3, 4 and 5. It is noted that as seen from the above formula,there are some ZC chains, but they need not have the same length and maybe have arbitrary length.

In a preferred embodiment, as shown below, “the number of such C atomswhich are linearly connected via the Z group in R^(a)” is 1 (leftformula) or 2 (right formula) in all chains.

In one embodiment, the number of such C atoms which are linearlyconnected via the Z group in R^(a) is 1 or 2, preferably 1.

In the formula, R² is —Y—SiR⁵ _(n)R⁶ _(3-n).

Y is each independently at each occurrence a divalent organic group.

In a preferable embodiment, Y is a C₁₋₆ alkylene group,—(CH₂)_(g′)—O—(CH₂)_(h′)— (wherein g′ is an integer of 0-6, for example,an integer of 1-6, and h′ is an integer of 0-6, for example, an integerof 1-6), or -phenylene-(CH₂)_(i′)— (wherein i′ is an integer of 0-6).These groups may be substituted with, for example, one or moresubstituents selected form a fluorine atom, a C₁₋₆ alkyl group, a C₂₋₆alkenyl group, and a C₂₋₆ alkynyl group.

In one embodiment, Y may be a C₁₋₆ alkylene group, —O—(CH₂)_(h′)— or-phenylene-(CH₂)_(i′)—. When Y is the above group, a light resistance,in particular an ultraviolet resistance, may be increased.

R⁵ is each independently at each occurrence a hydroxyl group or ahydrolyzable group.

The “hydrolyzable group” as used herein represents a group which is ableto undergo a hydrolysis reaction. Examples of the hydrolyzable groupinclude —OR, —OCOR, —O—N═C(R)₂, —N(R)₂, —NHR, halogen (wherein R is asubstituted or non-substituted alkyl group having 1-4 carbon atoms),preferably —OR (an alkoxy group). Examples of R include anon-substituted alkyl group such as a methyl group, an ethyl group, apropyl group, an isopropyl group, a n-butyl group, an isobutyl group; asubstituted alkyl group such as a chloromethyl group. Among them, analkyl group, in particular a non-substituted alkyl group is preferable,a methyl group or an ethyl group is more preferable. The hydroxyl groupmay be, but is not particularly limited to, a group generated byhydrolysis of a hydrolyzable group.

Preferably, R⁵ is —OR wherein R is a substituted or unsubstituted C₁₋₃alkyl group, more preferably an ethyl group or a methyl group, inparticular a methyl group.

In the formula, R⁶ is each independently at each occurrence a hydrogenatom or a lower alkyl group. The lower alkyl group is preferably analkyl group having 1-20 carbon atoms, more preferably an alkyl grouphaving 1-6 carbon atoms, further preferably a methyl group.

n is an integer of 1-3, preferably 2 or 3, more preferably 3,independently per unit —Y—SiR⁵ _(n)R⁶ _(3-n).

In the formula, R³ is each independently at each occurrence a hydrogenatom or a lower alkyl group. The lower alkyl group is preferably analkyl group having 1-20 carbon atoms, more preferably an alkyl grouphaving 1-6 carbon atoms, further preferably a methyl group.

In the formula, p is each independently at each occurrence an integer of0-3; q is each independently at each occurrence an integer of 0-3; r iseach independently at each occurrence an integer of 0-3. The sum of p, qand r is 3.

In a preferable embodiment, in R^(a′) (when R^(a′) is absent, R^(a)) atthe terminal of R^(a), q is preferably 2 or more, for example 2 or 3,more preferably 3.

In the formula, R^(b) is each independently at each occurrence —Y—SiR⁵_(n)R⁶ _(3-n). Y, R⁵, R⁶ and n are as defined for R².

In the formula, R^(c) is each independently at each occurrence ahydrogen atom or a lower alkyl group. The lower alkyl group ispreferably an alkyl group having 1-20 carbon atoms, more preferably analkyl group having 1-6 carbon atoms, further preferably a methyl group.

In the formula, k is each independently at each occurrence an integer of0-3; 1 is each independently at each occurrence an integer of 0-3; and mis each independently at each occurrence an integer of 0-3. The sum ofk, l and m is 3.

In one embodiment, at least one k is 2 or 3, preferably 3.

In one embodiment, k is 2 or 3, preferably 3.

In one embodiment, l is 2 or 3, preferably 3.

In the formula (1a) and (1b), at least one q is 2 or 3, or at least onel is 2 or 3. That is, there are at least two —Y—SiR⁵ _(n)R⁶ _(3-n)groups in the formula.

In the perfluoro(poly)ether group containing silane compound of theformula (1a) or the formula (1b), an average molecular weight of theRf-PFPE moiety is not particularly limited to, and is 500-30,000,preferably 1,500-30,000, more preferably 2,000-10,000.

The perfluoro(poly)ether group containing silane compound of the formula(1a) or the formula (1b) may have, but are not limited to, an averagemolecular weight of 5×10²-1×10⁵. Among such range, in view of frictiondurability, the compound has preferably 2,000-32,000, more preferably2,500-12,000. It is noted that the “average molecular weight” in thepresent invention means a number average molecular weight, and the“average molecular weight” is defined as a value measured by using¹⁹F-NMR.

The perfluoro(poly)ether group containing silane compound of the formula(1a) or the formula (1b) can be prepared by a combination of knownmethods. For example, a compound of the formula (1a′) wherein X is adivalent group can be prepared below, although the present invention isnot limited thereto.

A group containing a double bond (preferably allyl), and a halogen(preferably bromo) are introduced into polyol of HO—X—C(YOH)₃ (wherein Xand Y are each independently a divalent organic group) to obtain ahalide having a double bond of Hal-X—C(Y—O—R—CH═CH₂)₃ (wherein Hal ishalogen, for example Br, and R is a divalent organic group, for examplean alkylene group). Then, halogen at the terminal is reacted with aperfluoropolyether group containing alcohol of R^(PFPE)—OH (whereinR^(PFPE) is a perfluoropolyether group containing group.) to obtainR^(PFPE)—O—X—C(Y—O—R—CH═CH₂)₃. Then, —CH═CH₂ at the terminal is reactedwith HSiCl₃ and an alcohol or HSiR⁵ ₃ to obtainR^(PFPE)—O—X—C(Y—O—R—CH₂—CH₂—SiR⁵ ₃)₃.

Those skilled in the art can appropriately select a preferable range ofa reaction condition for preparing the perfluoro(poly)ether groupcontaining silane compound of the present invention can be selected bythose skilled in the art.

Next, the surface-treating agent of the present invention will bedescribed.

The surface-treating agent of the present invention comprises at leastone the perfluoro(poly)ether group containing silane compound of theformula (1a) or the formula (1b).

The surface-treating agent of the present invention can provide a basematerial with water-repellency, oil-repellency, antifouling property,surface slip property and friction durability, and can be suitably usedas an antifouling-coating agent or a water-proof coating agent, althoughthe present invention is not particularly limited thereto.

In one embodiment, the surface-treating agent of the present inventioncomprises at least one compound of the formula (1a) or the formula (1b)wherein x is a divalent organic group, α and β are 1.

In one embodiment, the surface-treating agent of the present inventioncomprises at least one compound of the formula (1a) or the formula (1b)wherein l is 3 and n is 3.

In one embodiment, the surface-treating agent of the present inventioncomprises the compound of the formula (1a).

The above-mentioned surface-treating agent may comprise other componentsin addition to the compound of the formula (1a) or the formula (1b).Examples of the other components include, but are not particularlylimited to, for example, a (non-reactive) fluoropolyether compound whichmay be also understood as a fluorine-containing oil, preferably aperfluoro(poly)ether compound (hereinafter, referred to as “thefluorine-containing oil”), a (non-reactive) silicone compound which maybe also understood as a silicone oil (hereinafter referred to as “asilicone oil”), a catalyst, and the like.

Examples of the above-mentioned fluorine-containing oil include, but arenot particularly limited to, for example, a compound of the followinggeneral formula (3) (a perfluoro(poly)ether compound).

R²¹—(OC₄F₈)_(a′)—(OC₃F₆)_(b′)—(OC₂F₄)_(c′)—(OCF₂)_(d′)—R²²  (3)

In the formula, R²¹ represents a C₁₋₁₆ alkyl group which may besubstituted by one or more fluorine atoms (preferably, a C₁₋₁₆perfluoroalkyl group), R²² represents a C₁₋₁₆ alkyl group which may besubstituted by one or more fluorine atoms (preferably, a C₁₋₁₆perfluoroalkyl group), a fluorine atom or a hydrogen atom, and morepreferably, R²¹ and R²² is each independently a C₁₋₃ perfluoroalkylgroup.

Subscripts a′, b′, c′ and d′ represent the repeating number of each offour repeating units of perfluoropolyether which constitute a mainbackbone of the polymer, and are each independently an integer of 0 ormore and 300 or less, and the sum of a′, b′, c′ and d′ is at least 1,preferably 1-300, more preferably 20-300. The occurrence order of therespective repeating units in parentheses with the subscript a′, b′, c′or d′ is not limited in the formulae. Among these repeating units, the—(OC₄F₈)— group may be any of —(OCF₂CF₂CF₂CF₂)—, —(OCF(CF₃)CF₂CF₂)—,—(OCF₂CF(CF₃)CF₂)—, —(OCF₂CF₂CF(CF₃))—, —(OC(CF₃)₂CF₂)—,—(OCF₂C(CF₃)₂)—, —(OCF(CF₃)CF(CF₃))—, —(OCF(C₂F₅)CF₂)— and—(OCF₂CF(C₂F₅))—, preferably —(OCF₂CF₂CF₂CF₂). The —(OC₃F₆)— group maybe any of —(OCF₂CF₂CF₂)—, —(OCF(CF₃)CF₂)— and —(OCF₂CF(CF₃))—,preferably —(OCF₂CF₂CF₂)—. The —(OC₂F₄)— group may be any of —(OCF₂CF₂)—and —(OCF(CF₃))—, preferably —(OCF₂CF₂)—.

Examples of the perfluoropolyether compound of the above general formula(3) include a compound of any of the following general formulae (3a) and(3b) (may be one compound or a mixture of two or more compounds).

R²¹—(OCF₂CF₂CF₂)_(b″)—R²²  (3a)

R²¹—(OCF₂CF₂CF₂CF₂)_(a″)—(OCF₂CF₂CF₂)_(b″)—(OCF₂CF₂)_(c″)—(OCF₂)_(d″)—R²²  (3b)

In these formulae:

R²¹ and R²² are as defined above; in the formula (3a), b″ is an integerof 1 or more and 100 or less; and in the formula (3b), a″ and b″ areeach independently an integer of 0 or more and 30 or less, and c″ and d″are each independently an integer of 1 or more and 300 or less. Theoccurrence order of the respective repeating units in parentheses withthe subscript a″, b″, c″ or d″ is not limited in the formulae.

The above-mentioned fluorine-containing oil may have an averagemolecular weight of 1,000-30,000. By having such average molecularweight, high surface slip property can be obtained.

The fluorine-containing oil may be contained in the surface-treatingagent of the present invention, for example, at 0-500 parts by mass,preferably 0-400 parts by mass, more preferably 25-400 parts by masswith respect to 100 parts by mass of the PFPE containing silane compoundof the present invention (as the total mass when two or more compoundsare used; hereinafter the same shall apply).

The compound of the general formula (3a) and the compound of the generalformula (3b) may be used alone or in combination. The compound of thegeneral formula (3b) is preferable than the compound of the generalformula (3a) since the compound of the general formula (3b) provideshigher surface slip property than the compound of the general formula(3a). When they are used in combination, the ratio by mass of thecompound of the general formula (3a) to the compound of the generalformula (3b) is preferably 1:1 to 1:30, more preferably 1:1 to 1:10. Byapplying such ratio by mass, a perfluoropolyether group-containingsilane-based coating which provides a good balance of surface slipproperty and friction durability can be obtained.

In one embodiment, the fluorine-containing oil comprises one or morecompounds of the general formula (3b). In such embodiment, the massratio of the compound of the formula (1a) or the formula (1b) to thecompound of the formula (3b) in the surface-treating agent is preferably4:1 to 1:4.

In one preferable embodiment, the surface-treating agent of the presentinvention comprises the compound of the formula (1a) or the formula (1b)wherein PFPE is —(OCF₂CF₂CF₂)_(b)— (b is an integer of 1-200) and thecompound of the formula (3b). By forming a surface-treating layer byusing such surface-treating agent with a wet coating method or a vacuumdeposition method, preferably vacuum deposition, excellent surface slipproperty and friction durability can be obtained.

In one preferable embodiment, the surface-treating agent of the presentinvention comprises the compound wherein PFPE represents—(OC₄F₈)_(a)—(OC₃F₆)_(b)—(OC₂F₄)_(c)—(OCF₂)_(d)— wherein a and b areeach independently an integer of 0 or more and 30 or less, preferably 0or more and 10 or less, and c and d are each independently an integer of1 or more and 200 or less, and the sum of a, b, c and d is an integer of10 or more and 200 or less. The occurrence order of the respectiverepeating units in parentheses with the subscript α, b, c or d is notlimited in the formula and the compound of the formula (3b). By forminga surface-treating layer by using such surface-treating agent with a wetcoating method or a vacuum deposition method, preferably vacuumdeposition, more excellent surface slip property and friction durabilitycan be obtained.

In these embodiments, an average molecular weight of the compound of theformula (3a) is preferably 2,000-8,000.

In these embodiments, an average molecular weight of the compound of theformula (3b) is preferably 2,000-30,000. An average molecular weight ofthe compound of the formula (3b) is preferably 8,000-30,000 when asurface-treating layer is formed by a dry coating method, for example,vacuum deposition, and is preferably 2,000-10,000, in particular3,000-5,000 when a surface-treating layer is formed by using a wetcoating method, for example, spray coating.

In a preferable embodiment, when a surface-treating layer is formed byusing vacuum deposition, an average molecular weight of thefluorine-containing oil may be higher than an average molecular weightof the compound of the formula (1a) and the formula (1b). By selectingsuch average molecular weights of the compound of the formula (1a) andthe formula (1b) and the fluorine-containing oil, more excellent surfaceslip property and friction durability can be obtained.

From the other point of view, the fluorine-containing oil may be acompound of the general formula Rf′—F wherein Rf′ is a C₅₋₁₆perfluoroalkyl group. The compound of Rf′—F is preferable because thecompound has high affinity for the compound of the formula (1a) and theformula (1b) wherein Rf is a C₁₋₁₆ perfluoroalkyl group.

The fluorine-containing oil contributes to increasing of surface slipproperty of the surface-treating layer.

Examples of the above-mentioned silicone oil include, for example, aliner or cyclic silicone oil having 2,000 or less siloxane bonds. Theliner silicone oil may be so-called a straight silicone oil and amodified silicon oil. Examples of the straight silicone oil includedimethylsilicone oil, methylphenylsilicone oil, andmethylhydrogensilicone oil. Examples of the modified silicone oilinclude that which is obtained by modifying a straight silicone oil withalkyl, aralkyl, polyether, higher fatty acid ester, fluoroalkyl, amino,epoxy, carboxyl, alcohol, or the like. Examples of the cyclic siliconeoil include, for example, cyclic dimethylsiloxane oil.

The silicone oil may be contained in the surface-treating agent of thepresent invention, for example, at 0-300 parts by mass, preferably50-200 parts by mass with respect to 100 parts by mass of the PFPEcontaining silane compound of the present invention (as the total masswhen two or more compounds are used; hereinafter the same shall apply).

The silicone oil contributes to increasing of surface slip property ofthe surface-treating layer.

Examples of the above-mentioned catalyst include an acid (for example,acetic acid, trifluoroacetic acid, etc.), a base (for example, ammonia,triethylamine, diethylamine, etc.), a transition metal (for example, Ti,Ni, Sn, etc.), and the like.

The catalyst facilitates hydrolysis and dehydration-condensation of thePFPE containing silane compound of the present invention to facilitate aformation of the surface-treating layer.

Examples of the other components other than the above-mentionedcomponents include, for example, tetraethoxysilane,methyltrimethoxysilane, 3-aminopropyltrimethoxysilane,3-glycidoxypropyltrimethoxysilane, methyltriacetoxysilane, and the like.

The surface-treating agent of the present invention is impregnated intoa porous material, for example, a porous ceramic material, a metal fiberfor example that obtained by solidifying a steel wool to obtain apellet. The pellet can be used, for example, in vacuum deposition.

Next, the article of the present invention will be described.

The article of the present invention comprises a base material and alayer (surface-treating layer) which is formed from the PFPE containingsilane compound or the surface-treating agent of the present invention(hereinafter, referred to simply as “surface-treating agent” as arepresentative thereof) on the surface of the base material. Thisarticle can be produced, for example, as follows.

Firstly, the base material is provided. The base material usable in thepresent invention may be composed of any suitable material such as aglass, a resin (may be a natural or synthetic resin such as a commonplastic material, and may be in form of a plate, a film, or others), ametal (may be a simple substance of a metal such as aluminum, copper, oriron, or a complex such as alloy or the like), a ceramic, asemiconductor (silicon, germanium, or the like), a fiber (a fabric, anon-woven fabric, or the like), a fur, a leather, a wood, a pottery, astone, an architectural member or the like.

For example, when an article to be produced is an optical member, amaterial constituting the surface of the base material may be a materialfor an optical member, for example, a glass or a transparent plastic.For example, when an article to be produced is an optical member, anylayer (or film) such as a hard coating layer or an antireflection layermay be formed on the surface (outermost layer) of the base material. Asthe antireflection layer, either a single antireflection layer or amulti antireflection layer may be used. Examples of an inorganicmaterial usable in the antireflection layer include SiO₂, SiO, ZrO₂,TiO₂, TiO, Ti₂O₃, Ti₂O₅, Al₂O₃, Ta₂O₅, CeO₂, MgO, Y₂O₃, SnO₂, MgF₂, WO₃,and the like. These inorganic materials may be used alone or incombination with two or more (for example, as a mixture). When multiantireflection layer is formed, preferably, SiO₂ and/or SiO are used inthe outermost layer. When an article to be produced is an optical glasspart for a touch panel, it may have a transparent electrode, forexample, a thin layer comprising indium tin oxide (ITO), indium zincoxide, or the like on a part of the surface of the base material(glass). Furthermore, the base material may have an insulating layer, anadhesive layer, a protecting layer, a decorated frame layer (I-CON), anatomizing layer, a hard coating layer, a polarizing film, a phasedifference film, a liquid crystal display module, and the like,depending on its specific specification.

The shape of the base material is not specifically limited. The regionof the surface of the base material on which the surface-treating layershould be formed may be at least a part of the surface of the basematerial, and may be appropriately determined depending on use, thespecific specification, and the like of the article to be produced.

The base material may be that of which at least the surface consists ofa material originally having a hydroxyl group. Examples of such materialinclude a glass, in addition, a metal on which a natural oxidized filmor a thermal oxidized film is formed (in particular, a base metal), aceramic, a semiconductor, and the like. Alternatively, as in a resin,when the hydroxyl groups are present but not sufficient, or when thehydroxyl group is originally absent, the hydroxyl group can beintroduced on the surface of the base material, or the number of thehydroxyl group can be increased by subjecting the base material to anypretreatment. Examples of the pretreatment include a plasma treatment(for example, corona discharge) or an ion beam irradiation. The plasmatreatment may be suitably used to introduce the hydroxyl group into orincrease it on the surface of the base material, further, to clarify thesurface of the base material (remove foreign materials, and the like).Alternatively, other examples of the pretreatment include a methodwherein a monolayer of a surface adsorbent having a carbon-carbonunsaturated bond group is formed on the surface of the base material byusing a LB method (Langmuir-Blodgett method) or a chemical adsorptionmethod beforehand, and then, cleaving the unsaturated bond under anatmosphere of oxygen and nitrogen.

Alternatively, the base material may be that of which at least thesurface consists of a material comprising other reactive group such as asilicon compound having one or more Si—H groups or alkoxysilane.

Next, the film of the above surface-treating agent of the presentinvention is formed on the surface of the base material, and the film ispost-treated, as necessary, and thereby the surface-treating layer isformed from the surface-treating agent.

The formation of the film of the surface-treating agent of the presentinvention can be performed by applying the above surface-treating agenton the surface of the base material such that the surface-treating agentcoats the surface. The method of coating is not specifically limited.For example, a wet coating method or a dry coating method can be used.

Examples of the wet coating method include dip coating, spin coating,flow coating, spray coating, roll coating, gravure coating, and asimilar method.

Examples of the dry coating method include deposition (usually, vacuumdeposition), sputtering, CVD and a similar method. The specific examplesof the deposition method (usually, vacuum deposition) include resistanceheating, electron beam, high-frequency heating using microwave, etc.,ion beam, and a similar method. The specific examples of the CVD methodinclude plasma-CVD, optical CVD, thermal CVD and a similar method. Thedeposition method is will be described below in more detail.

Additionally, coating can be performed by an atmospheric pressure plasmamethod.

When the wet coating method is used, the surface-treating agent of thepresent invention is diluted with a solvent, and then it is applied tothe surface of the base material. In view of stability of thesurface-treating agent of the present invention and volatile property ofthe solvent, the following solvents are preferably used: an aliphaticperfluorohydrocarbon having 5-12 carbon atoms (for example,perfluorohexane, perfluoromethylcyclohexane andperfluoro-1,3-dimethylcyclohexane); an aromatic polyfluorohydrocarbon(for example, bis(trifluoromethyl)benzene); an aliphaticpolyfluorohydrocarbon (for example, C₆F₁₃CH₂CH₃ (for example, ASAHIKLIN(registered trademark) AC-6000 manufactured by Asahi Glass Co., Ltd.),1,1,2,2,3,3,4-heptafluorocyclopentane (for example, ZEORORA (registeredtrademark) H manufactured by Nippon Zeon Co., Ltd.); a hydrofluoroether(HFE) (for example, an alkyl perfluoroalkyl ether such asperfluoropropyl methyl ether (C₃F₇OCH₃) (for example, Novec (trademark)7000 manufactured by Sumitomo 3M Ltd.), perfluorobutyl methyl ether(C₄F₉OCH₃) (for example, Novec (trademark) 7100 manufactured by Sumitomo3M Ltd.), perfluorobutyl ethyl ether (C₄F₉OC₂H₅) (for example, Novec(trademark) 7200 manufactured by Sumitomo 3M Ltd.), and perfluorohexylmethyl ether (C₂F₅CF(OCH₃)C₃F₇) (for example, Novec (trademark) 7300manufactured by Sumitomo 3M Ltd.) (the perfluoroalkyl group and thealkyl group may be liner or branched)), or CF₃CH₂OCF₂CHF₂ (for example,ASAHIKLIN (registered trademark) AE-3000 manufactured by Asahi GlassCo., Ltd.) and the like. These solvents may be used alone or as amixture of 2 or more compound. Among them, the hydrofluoroether ispreferable, perfluorobutyl methyl ether (C₄F₉OCH₃) and/or perfluorobutylethyl ether (C₄F₉OC₂H₅) are particularly preferable.

When the dry coating method is used, the surface-treating agent of thepresent invention may be directly subjected to the dry coating method,or may be diluted with a solvent, and then subjected to the dry coatingmethod.

The formation of the film is preferably performed so that thesurface-treating agent of the present invention is present together witha catalyst for hydrolysis and dehydration-condensation in the coating.Simply, when the wet coating method is used, after the surface-treatingagent of the present invention is diluted with a solvent, and just priorto applying it to the surface of the base material, the catalyst may beadded to the diluted solution of the surface-treating agent of thepresent invention. When the dry coating method is used, thesurface-treating agent of the present invention to which a catalyst hasbeen added is used itself in deposition (usually, vacuum deposition), orpellets may be used in the deposition (usually, the vacuum deposition),wherein the pellets is obtained by impregnating a porous metal such asiron or copper with the surface-treating agent of the present inventionto which the catalyst has been added.

As the catalyst, any suitable acid or base can be used. As the acidcatalyst, for example, acetic acid, formic acid, trifluoroacetic acid,or the like can be used. As the base catalyst, for example, ammonia, anorganic amine, or the like can be used.

Next, the film is post-treated as necessary. This post-treatment is, butnot limited to, a treatment in which water supplying and dry heating aresequentially performed, in more particular, may be performed as follows.

After the film of the surface-treating agent of the present invention isformed on the surface of the base material as mentioned above, water issupplied to this film (hereinafter, referred to as precursor coating).The method of supplying water may be, for example, a method using dewcondensation due to the temperature difference between the precursorcoating (and the base material) and ambient atmosphere or spraying ofwater vapor (steam), but not specifically limited thereto.

It is considered that, when water is supplied to the precursor coating,water acts on a hydrolyzable group bonding to Si present in theperfluoro(poly)ether group containing silane compound in thesurface-treating agent of the present invention, thereby enabling rapidhydrolysis of the compound.

The supplying of water may be performed under an atmosphere, forexample, at a temperature of 0-250° C., preferably 60° C. or more, morepreferably 100° C. or more and preferably 180° C. or less, morepreferably 150° C. By supplying water at such temperature range,hydrolysis can proceed. The pressure at this time is not specificallylimited but simply may be ambient pressure.

Then, the precursor coating is heated on the surface of the basematerial under a dry atmosphere over 60° C. The method of dry heatingmay be to place the precursor coating together with the base material inan atmosphere at a temperature over 60° C., preferably over 100° C., andfor example, of 250° C. or less, preferably of 180° C. or less, and atunsaturated water vapor pressure, but not specifically limited thereto.The pressure at this time is not specifically limited but simply may beambient pressure.

Under such atmosphere, between the PFPE containing silane compound ofthe present inventions, the groups (being hydroxyl groups when all R¹are hydroxyl groups in the above mentioned compound of any of theformula (1a) or the formula (1b); hereinafter the same shall apply)bonding to Si after hydrolysis are rapidly dehydration-condensed witheach other. Furthermore, between the compound and the base material, thegroup bonding to Si in the compound after hydrolysis and a reactivegroup present on the surface of the base material are rapidly reacted,and when the reactive group present on the surface of the base materialis a hydroxyl group, dehydration-condensation is caused. As the result,the bond between the PFPE containing silane compounds of the presentinvention is formed, and the bond between the compound and the basematerial is formed. It is noted that if present, the fluorine-containingoil and/or the silicone oil is held or acquired by an affinity to theperfluoropolyether group containing silane compound.

The above supplying of water and dry heating may be sequentiallyperformed by using a superheated water vapor.

The superheated water vapor is a gas which is obtained by heating asaturated water vapor to a temperature over the boiling point, whereinthe gas, under an ambient pressure, has become to have a unsaturatedwater vapor pressure by heating to a temperature over 100° C., generallyof 250° C. or less, for example, of 180° C. or less, and over theboiling point. When the base material on which the precursor coating isformed is exposed to a superheated water vapor, firstly, due to thetemperature difference between the superheated water vapor and theprecursor coating of a relatively low temperature, dew condensation isgenerated on the surface of the precursor coating, thereby supplyingwater to the precursor coating. Presently, as the temperature differencebetween the superheated water vapor and the precursor coating decreases,water on the surface of the precursor coating is evaporated under thedry atmosphere of the superheated water vapor, and an amount of water onthe surface of the precursor coating gradually decreases. During theamount of water on the surface of the precursor coating is decreasing,that is, during the precursor coating is under the dry atmosphere, theprecursor coating on the surface of the base material contacts with thesuperheated water vapor, as a result, the precursor coating is heated tothe temperature of the superheated water vapor (temperature over 100° C.under ambient pressure). Therefore, by using a superheated water vapor,supplying of water and dry heating are enabled to be sequentiallycarried out simply by exposing the base material on which the precursorcoating is formed to a superheated water vapor.

As mentioned above, the post-treatment can be performed. It is notedthat though the post-treatment may be performed in order to furtherincrease friction durability, it is not essential in the producing ofthe article of the present invention. For example, after applying thesurface-treating agent to the surface of the base material, it may beenough to only stand the base material.

As described above, the surface-treating layer derived from the film ofthe surface-treating agent of the present invention is formed on thesurface of the base material to produce the article of the presentinvention. The surface-treating layer thus formed has high surface slipproperty and high friction durability. Furthermore, thissurface-treating layer may have water-repellency, oil-repellency,antifouling property (for example, preventing from adhering a foulingsuch as fingerprints), waterproof property (preventing the ingress ofwater into an electrical member, and the like), surface slip property(or lubricity, for example, wiping property of a fouling such asfingerprints and excellent tactile feeling in a finger) depending on acomposition of the surface-treating agent used, in addition to highfriction durability, thus may be suitably used as a functional thinfilm.

Therefore, the present invention further provides an optical materialhaving the hardened material on the outermost layer.

Examples of the optical material include preferably a variety of opticalmaterials in addition to the optical material for displays, or the likeexemplified in below: for example, displays such as a cathode ray tube(CRT; for example, TV, personal computer monitor), a liquid crystaldisplay, a plasma display, an organic EL display, an inorganic thin-filmEL dot matrix display, a rear projection display, a vacuum fluorescentdisplay (VFD), a field emission display (FED; Field Emission Display),or a protective plate of such displays, or that in which these displaysand protective plates have been subjected to antireflection treatment ontheir surface.

The article having the surface-treating layer obtained according to thepresent invention is not specifically limited to, but may be an opticalmember. Examples of the optical member include the followings: lens ofglasses, or the like; a front surface protective plate, anantireflection plate, a polarizing plate, or an anti-glare plate on adisplay such as PDP and LCD; a touch panel sheet of an instrument suchas a mobile phone or a personal digital assistance; a disk surface of anoptical disk such as a Blu-ray disk, a DVD disk, a CD-R or MO; anoptical fiber, and the like.

The article having the surface-treating layer obtained according to thepresent invention may be also a medical equipment or a medical material.

The thickness of the surface-treating layer is not specifically limited.For the optical member, the thickness of the surface-treating layer iswithin the range of 1-50 nm, 1-30 nm, preferably 1-15 nm, in view ofoptical performance, surface slip property, friction durability andantifouling property.

Hereinbefore, the article produced by using the surface-treating agentof the present invention is described in detail. It is noted that anapplication, a method for using or a method for producing the articleare not limited to the above exemplification.

EXAMPLES

The surface-treating agent of the present invention will be described indetail through Examples, although the present invention is not limitedto Examples. It is noted that the occurrence order of the four repeatingunits (CF₂O), (CF₂CF₂O), (CF(CF₃)CF₂O), (CF₂CF₂CF₂O) and (CF₂CF₂CF₂CF₂O)constituting the perfluoropolyether of is not limited in Examples.

Synthesizing Example 1

To a four necked flask of 100 mL provided with a reflux condenser, athermometer and a stirrer, NaH (4.62 g), and tetrabutylammonium bromide(0.41 g) were added. Then, 1,3-bis(trifluoromethyl)benzene (23 g),1,4-dibromobutane (42 g), and pentaerythritol triallyl ether (10 g) wereadded and stirred at 65° C., and then separated and purified to obtainpentaerythritol triallyl ether bromo adduct (A) (5.23 g).

Pentaerythritol Triallyl Ether Bromo Adduct (A):

BrCH₂CH₂CH₂CH₂OCH₂C(CH₂OCH₂CH═CH₂)₃

Synthesizing Example 2

To a four necked flask of 100 mL provided with a reflux condenser, athermometer and a stirrer, a perfluoropolyether modified alcoholcompound of the average composition: CF₃O(CF₂CF₂O)₂O(CF₂O)₁₆CF₂CH₂OH(with proviso that although the compound comprising a small amount ofthe repeating units (CF₂CF₂CF₂CF₂O) and/or (CF₂CF₂CF₂O) in the mixture,it was not taken into consideration since it was a very small amount)(8.96 g), 1,3-bis(trifluoromethyl)benzene (51 g), and KOH (0.39 g) wereadded and stirred at 70° C. Then, pentaerythritol triallyl ether bromoadduct (A) (3.60 g) obtained in Synthesizing Example 1, andtetrabutylammonium bromide (0.14 g) were added and stirred at 70° C.,and then separated and purified to obtain perfluoropolyether groupcontaining allyloxy compound (B) having an allyl group at the terminal(4.86 g).

Perfluoropolyether Group Containing Allyloxy Compound (B):

CF₃O(CF₂CF₂O)₂O(CF₂O)₁₆CF₂CH₂OCH₂CH₂CH₂CH₂OCH₂C(CH₂OCH₂CH═CH₂)₃

Synthesizing Example 3

To a four necked flask of 50 mL provided with a reflux condenser, athermometer and a stirrer, perfluoropolyether group containing allyloxycompound (B) (3.33 g) obtained in Synthesizing Example 2,1,3-bis(trifluoromethyl)benzene (7.24 g), and triacetoxysilane (0.01 g)were added and stirred for 30 minutes. Then, trichlorosilane (1.16 g)and a xylene solution (0.03 ml) containing Pt complex of1,3-divinyl-1,1,3,3-tetramethyldisiloxane at 2% were added and stirredat 60° C. for 3 hours. Then, volatile content was distilled off under areduced pressure to obtain, and a mixture of methanol (0.13 g) andtrimethyl orthoformate (5.25 g) was added, and then, stirred at 50° C.and separate and purified to obtain perfluoropolyether group containingsilane compound (C) having trimethoxysilyl group at the terminal (3.12g).

Perfluoropolyether Group Containing Silane Compound (C):

CF₃O(CF₂CF₂O)₂O(CF₂O)₁₆CF₂CH₂OCH₂CH₂CH₂CH₂OCH₂C(CH₂OCH₂CH₂CH₂Si(O Me)₃)₃

Synthesizing Example 4

To a four necked flask of 100 mL provided with a reflux condenser, athermometer and a stirrer, perfluoropolyether modified alcohol compound(8.5 g) of the average composition:CF₃CF₂CF₂O(CF₂CF₂CF₂O)₂₀OCF₂CF₂CH₂OH, 1,3-bis(trifluoromethyl)benzene(45 g) and KOH (0.33 g) were added and stirred at 70° C. Then,pentaerythritol triallyl ether bromo adduct (A) (3.10 g) obtained inSynthesizing Example 1 and tetrabutylammonium bromide (0.12 g) wereadded and stirred at 70° C., and then separated and purified to obtainperfluoropolyether group containing allyloxy compound (D) having allylgroup at the terminal (4.81 g).

Perfluoropolyether Group Containing Allyloxy Compound (D):

CF₃CF₂CF₂O(CF₂CF₂CF₂O)₂OCF₂CF₂CH₂OCH₂CH₂CH₂CH₂OCH₂C(CH₂OCH₂CH═CH₂)₃

Synthesizing Example 5

To a four necked flask of 50 mL provided with a reflux condenser, athermometer and a stirrer, perfluoropolyether group containing allyloxycompound (D) (4.5 g) obtained in Synthesizing Example 4,1,3-bis(trifluoromethyl)benzene (8.87 g), and triacetoxysilane (0.01 g)were added and stirred for 30 minutes. Then, trichlorosilane (1.42 g)and a xylene solution (0.04 ml) containing Pt complex of1,3-divinyl-1,1,3,3-tetramethyldisiloxane at 2% were added and stirredat 60° C. for 3 hours. Then, volatile content was distilled off under areduced pressure to obtain, and a mixture of methanol (0.16 g) andtrimethyl orthoformate (6.44 g) was added, and then, stirred at 50° C.and separate and purified to obtain perfluoropolyether group containingsilane compound (E) having trimethoxysilyl group at the terminal (4.36g).

Perfluoropolyether Group Containing Silane Compound (E):

CF₃CF₂CF₂O(CF₂CF₂CF₂O)₂OCF₂CF₂CH₂OCH₂CH₂CH₂CH₂OCH₂C(CH₂OCH₂CH₂CH₂Si(OMe)₃)₃

Synthesizing Example 6

To a four necked flask of 50 mL provided with a reflux condenser, athermometer and a stirrer, perfluoropolyether group containing allyloxycompound of CF₃O(CF₂CF₂O)₂O(CF₂O)₁₆CF₂C(OCH₂CH═CH₂)(CH₂CH═CH₂)₂ (5.0 g)(with proviso that although the compound comprising a small amount ofthe repeating units (CF₂CF₂CF₂CF₂O) and/or (CF₂CF₂CF₂O) in the mixture,it was not taken into consideration since it was a very small amount),1,3-bis(trifluoromethyl)benzene (9.0 g), and triacetoxysilane (0.01 g)were added and stirred for 30 minutes. Then, trichlorosilane (1.50 g)and a xylene solution (0.05 ml) containing Pt complex of1,3-divinyl-1,1,3,3-tetramethyldisiloxane at 2% were added and stirredat 60° C. for 3 hours. Then, volatile content was distilled off under areduced pressure to obtain, and a mixture of methanol (0.20 g) andtrimethyl orthoformate (7.0 g) was added, and then, stirred at 50° C.and separate and purified to obtain perfluoropolyether group containingsilane compound (F) having trimethoxysilyl group at the terminal (5.32g).

Perfluoropolyether Group Containing Silane Compound (F):

CF₃O(CF₂CF₂O)₂O(CF₂O)₁₆CF₂C[OCH₂CH₂CH₂Si(OMe)₃][CH₂CH₂CH₂Si(OMe)₃]₂

Synthesizing Example 7

To a four necked flask of 50 mL provided with a reflux condenser, athermometer and a stirrer, perfluoropolyether group containing allyloxycompound of CF₃CF₂CF₂O(CF₂CF₂CF₂O)₂OCF₂CF₂C(OCH₂CH═CH₂)(CH₂CH═CH₂)₂ (4.0g), 1,3-bis(trifluoromethyl)benzene (7.2 g), and triacetoxysilane (0.01g) were added and stirred for 30 minutes. Then, trichlorosilane (1.20 g)and a xylene solution (0.04 ml) containing Pt complex of1,3-divinyl-1,1,3,3-tetramethyldisiloxane at 2% were added and stirredat 60° C. for 3 hours. Then, volatile content was distilled off under areduced pressure to obtain, and a mixture of methanol (0.16 g) andtrimethyl orthoformate (5.6 g) was added, and then, stirred at 50° C.and separate and purified to obtain perfluoropolyether group containingsilane compound (G) having trimethoxysilyl group at the terminal (4.4g).

Perfluoropolyether Group Containing Silane Compound (G):

CF₃CF₂CF₂O(CF₂CF₂CF₂O)₂OCF₂CF₂C[OCH₂CH₂CH₂Si(OMe)₃][CH₂CH₂CH₂Si(OMe)₃]₂

Example 1

Compound (C) obtained in Synthesizing Example 3 was dissolved inhydrofluoroether (Novec HFE7200 manufactured by Sumitomo 3M Ltd.)) suchthat the concentration was 20 wt % to prepare Surface-treating agent 1.

Surface-treating agent 1 prepared in the above was vacuum deposited on achemical strengthening glass (Gorilla glass manufactured by CorningIncorporated; thickness: 0.7 mm). Processing condition of the vacuumdeposition was a pressure of 3.0×10⁻³ Pa. Firstly, silicon dioxide wasdeposited on the surface of this chemical strengthening glass in amanner of an electron-beam deposition. Subsequently, thesurface-treating agent of 2 mg (that is, it contained of 0.4 mg ofCompound (C)) was vacuum-deposited per one plate of the chemicalstrengthening glass (55 mm×100 mm). Then, the chemical strengtheningglass having the deposited layer was stood under a temperature of 20° C.and a humidity of 65% for 24 hours.

Example 2

The surface-treating agent was prepared and the surface-treating layerwas formed similarly to Example 1 except that Compound (E) obtained inSynthesis Example 5 was used in place of Compound (C).

Example 3

The surface-treating agent was prepared and the surface-treating layerwas formed similarly to Example 1 except that Compound (F) obtained inSynthesis Example 6 was used in place of Compound (C).

Example 4

The surface-treating agent was prepared and the surface-treating layerwas formed similarly to Example 1 except that Compound (G) obtained inSynthesis Example 7 was used in place of Compound (C).

Example 5

The surface-treating agent was prepared and the surface-treating layerwas formed similarly to Example 1 except that perfluoropolyether groupcontaining silane compound (H) shown below was used in place of Compound(C).

Perfluoropolyether Group Containing Silane Compound (H):

CF₃O(CF₂CF₂O)₂O(CF₂O)₁₆CF₂C[OC(O)NHCH₂CH₂CH₂Si(OMe)₃][CH₂CH₂CH₂Si(OMe)₃]₂

Comparative Examples 1-3

The surface-treating agent was prepared and the surface-treating layerwas formed similarly to Example 1 except that Control compounds 1-3shown below were used in place of Compound (C).

Control Compound 1

CF₃O(CF₂CF₂O)₂O(CF₂O)₁₋₆CF₂CH₂OCH₂CH₂CH₂Si(OCH₃)₃

Control Compound 2

wherein g is an integer of 1-6.

Control Compound 3

wherein g is an integer of 1-6.

Evaluation of Friction Durability

A static water contact angle of the surface-treating layers formed onthe surface of the base material in the above Examples and ComparativeExamples respectively was measured. The static water contact angle wasmeasured for 1 μL of water by using a contact angle measuring instrument(manufactured by KYOWA INTERFACE SCIENCE Co., Ltd.).

Firstly, as an initial evaluation, the static water contact angle of thesurface-treating layer of which the surface had not still contacted withanything after formation thereof was measured (the number of rubbing iszero). Then, as an evaluation of the friction durability, a steel woolfriction durability evaluation was performed. Specifically, the basematerial on which the surface-treating layer was formed was horizontallyarranged, and then, a steel wool (grade No. 0000, 5 mm×10 mm×10 mm) wascontacted with the exposed surface of the surface-treating layer and aload of 1000 gf was applied thereon. Then, the steel wool was shuttledat a rate of 140 mm/second while applying the load. The static watercontact angle (degree) was measured per 2,500 shuttling. The evaluationwas stopped when the measured value of the contact angle became to beless than 100 degree. The results are shown in Table 1 (in the table,the symbol “-” represents no measurement).

TABLE 1 Number of rubbing Contact Angle (degree) (times) Example 1Example 2 Example 3 Example 4 Example 5 0 113.1 113.8 113.4 113.0 113.22500 112.7 112.5 112.1 111.9 111.7 5000 112.3 111.4 112.0 109.5 108.87500 112.0 111.2 110.6 109.2 108.4 10000 112.3 108.2 107.1 107.5 107.412500 112.2 106.4 105.9 106.2 104.2 15000 111.1 106.1 104.7 104.0 103.817500 110.9 104.9 104.8 103.7 103.5 20000 109.6 104.5 103.9 102.6 102.422500 108.3 102.7 102.4 102.2 101.9 Number of Contact Angle (degree)rubbing Comparative Comparative Comparative (times) Example 1 Example 2Example 3 0 113.0 112.8 113.6 2500 104.0 110.9 108.2 5000 74.3 110.492.5 7500 — 107.2 — 10000 — 105.5 — 12500 — 104.2 — 15000 — 95.0 — 17500— — — 20000 — — — 22500 — — —

As understood from the above results, it was confirmed that Examples 1-5using the perfluoropolyether group containing silane compound of thepresent invention having some Si(OMe)₃ branching from a carbon atom ofthe main chain showed improved friction durability in comparison withComparative Examples 1-3 using the compounds having no such structure.

INDUSTRIAL APPLICABILITY

The present invention is suitably applied for forming a surface-treatinglayer on a surface of various base materials, in particular, an opticalmember in which transparency is required.

What is claimed is:
 1. A perfluoro(poly)ether group containing silanecompound of formula (1a) or formula (1b):(Rf-PFPE)_(β)-X—(CR^(a) _(k)R^(b) _(l)R^(c) _(m))_(α)  (1a)(R^(c) _(m)R^(b) _(l)R^(a) _(k)C)_(α)—X-PFPE-X—(CR^(a) _(k)R^(b)_(l)R^(c) _(m))_(α)  (1b) wherein: Rf is each independently at eachoccurrence a perfluoroalkyl group having 1-16 carbon atoms; PFPE is eachindependently at each occurrence a group of the formula:—(OC₄F₈)_(a)—(OC₃F₆)_(b)—(OC₂F₄)—(OCF₂)_(d)— wherein (OC₄F₈) is(OCF₂CF₂CF₂CF₂), (OC₃F₆) is (OCF₂CF₂CF₂), (OC₂F₄) is (OCF₂CF₂), a, b, cand d are each independently an integer of 0-200, the sum of a, b, c andd is 10-200, and the occurrence order of the respective repeating unitsin parentheses with the subscript α, b, c or d is not limited in theformula; X is each independently the following divalent organic group;R³¹—X^(c)—R³¹— wherein R³¹ is each independently a single bond,—(CH₂)_(s′)—, s′ is an integer of 1-6, X^(c) is —O—, or —CONR³⁴—, andR³⁴ is each independently at each occurrence a hydrogen atom or a C₁₋₆alkyl group, α is 1; β is 1; R^(b) is each independently at eachoccurrence —Y—SiR⁵ _(n)R⁶ _(3-n); Y is each independently at eachoccurrence a C₁₋₆ alkylene group or —(CH₂)_(g′)—O—(CH₂)_(h′)— wherein g′is an integer of 1-6, and h′ is an integer of 1-6; R⁵ is eachindependently at each occurrence a hydroxyl group, —OR, —OCOR,—O—N═C(R)₂, —N(R)₂, —NHR, or halogen wherein R is a substituted ornon-substituted alkyl group having 1-4 carbon atoms; R⁶ is eachindependently at each occurrence a hydrogen atom or an alkyl grouphaving 1-20 carbon atoms; n is an integer of 1-3 independently per unit—Y—SiR⁵ _(n)R⁶ _(3-n); k is 0; l is 3; and m is
 0. 2. Theperfluoro(poly)ether group containing silane compound according to claim1 wherein PFPE is a group of the following formula (iv):—(OC₂F₄—R⁸)_(n″)—  (iv) wherein R⁸ is a group selected from OC₂F₄, OC₃F₆and OC₄F₈, or a combination of 2 or 3 groups independently selected fromthese groups; OC₄F₈ is OCF₂CF₂CF₂CF₂, OC₃F₆ is OCF₂CF₂CF₂, OC₂F₄ isOCF₂CF₂, and n″ is an integer of 2-100.
 3. The perfluoro(poly)ethergroup containing silane compound according to claim 1 wherein X is eachindependently selected from the group consisting of: —CH₂O(CH₂)₂—,—CH₂O(CH₂)₃—, —CH₂O(CH₂)₆—, —CONH—(CH₂)₃—, —CON(CH₃)—(CH₂)₃—,—CONH—(CH₂)₆—, and —CON(CH₃)—(CH₂)₆—.
 4. The perfluoro(poly)ether groupcontaining silane compound according to claim 1 wherein Y is a C₃alkylene group, or —(CH₂)_(g′)—O—(CH₂)_(h′)— wherein g′ is 1, and h′ isan integer of 1-6.
 5. The perfluoro(poly)ether group containing silanecompound according to claim 1, having an average molecular weight of2,000-32,000.
 6. A surface-treating agent comprising at least oneperfluoro(poly)ether group containing silane compound of the formula(1a) and/or the formula (1b) according to claim
 1. 7. Thesurface-treating agent according to claim 6 further comprising one ormore components selected form a fluorine-containing oil, a silicone oiland a catalyst.
 8. The surface-treating agent according to claim 7wherein the fluorine-containing oil is one or more compounds of theformula (3):R²¹—(OC₄F₈)_(a′)—(OC₃F₆)_(b′)—(OC₂F₄)_(c′)—(OCF₂)_(d′)—R²²  (3) wherein:R²¹ is an alkyl group having 1-16 carbon atoms which may be substitutedby one or more fluorine atoms; R²² is an alkyl group having 1-16 carbonatoms which may be substituted by one or more fluorine atoms, a fluorineatom or a hydrogen atom; and a′, b′, c′ and d′ are the repeating numberof each of four repeating units of perfluoro(poly)ether whichconstitutes a main backbone of the polymer, and are each independentlyan integer of 0 or more and 300 or less, the sum of a′, b′, c′ and d′ is1 or more, and the occurrence order of the respective repeating units inparentheses with the subscript α′, b′, c′ and d′ is not limited in theformula.
 9. The surface-treating agent according to claim 7 wherein thefluorine-containing oil is one or more compounds of the formula (3a) or(3b):R²¹—(OCF₂CF₂CF₂)_(b″)—R²²  (3a)R²¹—(OCF₂CF₂CF₂CF₂)_(a″)—(OCF₂CF₂CF₂)_(b″)—(OCF₂CF₂)_(c″)—(OCF₂)_(d″)—R²²  (3b)wherein: R²¹ is an alkyl group having 1-16 carbon atoms which may besubstituted by one or more fluorine atoms; R²² is an alkyl group having1-16 carbon atoms which may be substituted by one or more fluorineatoms, a fluorine atom or a hydrogen atom; in the formula (3a), b″ is aninteger of 1 or more and 100 or less; in the formula (3b), a″ and b″ areeach independently an integer of 0 or more and 30 or less, and c″ and d″are each independently an integer of 1 or more and 300 or less; and theoccurrence order of the respective repeating units in parentheses withthe subscript a″, b″, c″ or d″ is not limited in the formula.
 10. Thesurface-treating agent according to claim 9 wherein a mass ratio of theperfluoro(poly)ether group containing silane compound of the formula(1a) or the formula (1b) and the compound of the formula (3b) is4:1-1:4.
 11. The surface-treating agent according to claim 9 wherein thecompound of the formula (3a) has a number average molecular weight of2,000-8,000.
 12. The surface-treating agent according to claim 9 whereinthe compound of the formula (3b) has a number average molecular weightof 2,000-30,000.
 13. The surface-treating agent according to claim 9wherein the compound of the formula (3b) has a number average molecularweight of 8,000-30,000.
 14. The surface-treating agent according toclaim 6 further comprising a solvent.
 15. The surface-treating agentaccording to claim 6 which is used as an antifouling-coating agent or awater-proof coating agent.
 16. The surface-treating agent according toclaim 6 for vacuum deposition.
 17. A pellet containing thesurface-treating agent according to claim
 6. 18. An article comprising abase material and a layer which is formed on a surface of the basematerial from the compound according to claim
 1. 19. The articleaccording to claim 18 wherein the article is an optical member.
 20. Thearticle according to claim 18 wherein the article is a display.
 21. Theperfluoro(poly)ether group containing silane compound according to claim1 wherein PFPE is —(OC₂F₄—OC₃F₆)_(n″)— or —(OC₂F₄—OC₄F₈)_(n″)— whereinOC₄F₈ is OCF₂CF₂CF₂CF₂, OC₃F₆ is OCF₂CF₂CF₂, OC₂F₄ is OCF₂CF₂, and n″ isan integer of 2-100.
 22. The perfluoro(poly)ether group containingsilane compound according to claim 1 wherein X is each independently thefollowing divalent organic group: R³¹—X^(c)—R³¹— wherein R³¹ is eachindependently a single bond, or —CH₂—, and X^(c) is —O—, or —CONH—. 23.The perfluoro(poly)ether group containing silane compound according toclaim 1 wherein X is each independently the following divalent organicgroup: R³¹—X^(c)—R³¹— wherein R³¹ is —CH₂—, and X^(c) is —O—.
 24. Theperfluoro(poly)ether group containing silane compound according to claim1 wherein X is each independently the following divalent organic group:R³¹—X^(c)—R³¹— wherein R³¹ is each independently a single bond or —CH₂—,and X^(c) is —CONH—.
 25. The perfluoro(poly)ether group containingsilane compound according to claim 1 wherein X is each independently thefollowing divalent organic group; R³¹—X^(c)—R³¹— wherein R³¹ is a singlebond, and X^(c) is —CONH—.
 26. The perfluoro(poly)ether group containingsilane compound according to claim 1 wherein Rf is each independently ateach occurrence a perfluoroalkyl group having 1-3; PFPE is eachindependently at each occurrence a group of the formula (iv):—(OC₂F₄—R⁸)_(n″)—  (iv) wherein R⁸ is a group selected from OC₂F₄, OC₃F₆and OC₄F₈, or a combination of 2 or 3 groups independently selected fromthese groups; OC₄F₈ is OCF₂CF₂CF₂CF₂, OC₃F₆ is OCF₂CF₂CF₂, OC₂F₄ isOCF₂CF₂, and n″ is an integer of 2-100; X is each independently thefollowing divalent organic group; —X^(c)—R³¹— wherein R³¹ is—(CH₂)_(s′)—, s′ is 1, X^(c) is —O— or —CONR³⁴—, and R³⁴ is a hydrogenatom, α is 1; β is 1; R^(b) is each independently at each occurrence—Y—SiR⁵ _(n)R⁶ _(3-n); Y is each independently at each occurrence a C₁₋₆alkylene group or —(CH₂)_(g′)—O—(CH₂)_(h′)— wherein g′ is an integer of1-6, and h′ is an integer of 1-6; R⁵ is each independently at eachoccurrence —OR wherein R is a methyl group or an ethyl group; n is 3; kis 0; l is 3; and m is
 0. 27. A perfluoro(poly)ether group containingsilane compound of formula (1a) or formula (1b):(Rf-PFPE)_(β)-X—(CR^(a) _(k)R^(b) _(l)R^(c) _(m))_(α)  (1a)(R^(c) _(m)R^(b) _(l)R^(a) _(k)C)_(α)—X-PFPE-X—(CR^(a) _(k)R^(b)_(l)R^(c) _(m))_(α)  (1b) wherein: Rf is each independently at eachoccurrence an alkyl group having 1-16 carbon atoms which may besubstituted by one or more fluorine atoms; PFPE is each independently ateach occurrence a group of the formula:—(OC₄F₈)_(a)—(OC₃F₆)_(b)—(OC₂F₄)_(c)—(OCF₂)_(d)— wherein a, b, c and dare each independently an integer of 0-200, the sum of a, b, c and d is1 or more, and the occurrence order of the respective repeating units inparentheses with the subscript α, b, c or d is not limited in theformula; X is a single bond, α is 1; β is 1; R^(a) is each independentlyat each occurrence —Z—CR¹ _(p)R² _(q)R³ _(r); Z is each independently ateach occurrence an oxygen atom, a C₁₋₆ alkylene group,—(CH₂)_(g)—O—(CH₂)_(h)— wherein g is an integer of 1-6 and h is aninteger of 0-6, or -phenylene-(CH₂)_(i)— wherein i is an integer of 0-6;R¹ is each independently at each occurrence R^(a); R^(a′) has the samedefinition as that of R^(a); in R^(a), the number of C atoms which arestraightly linked via the Z group is up to five; R² is eachindependently at each occurrence —Y—SiR⁵ _(n)R⁶ _(3-n); Y is eachindependently at each occurrence a C₁₋₆ alkylene group or—(CH₂)_(g′)—O—(CH₂)_(h′)— wherein g′ is an integer of 0-6, and h′ is aninteger of 1-6; R⁵ is each independently at each occurrence a hydroxylgroup, —OR, —OCOR, —O—N═C(R)₂, —N(R)₂, —NHR, or halogen wherein R is asubstituted or non-substituted alkyl group having 1-4 carbon atoms; R⁶is each independently at each occurrence a hydrogen atom or an alkylgroup having 1-20 carbon atoms; n is an integer of 1-3 independently perunit —Y—SiR⁵ _(n)R⁶ _(3-n); R³ is each independently at each occurrencea hydrogen atom or an alkyl group having 1-20 carbon atoms; p is eachindependently at each occurrence an integer of 0-3; q is eachindependently at each occurrence an integer of 0-3; r is eachindependently at each occurrence an integer of 0-3; R^(b) is eachindependently at each occurrence —Y—SiR⁵ _(n)R⁶ _(3-n); R^(c) is eachindependently at each occurrence a hydrogen atom or an alkyl grouphaving 1-20 carbon atoms; k is each independently at each occurrence aninteger of 0-3; l is each independently at each occurrence an integer of0-3; and m is each independently at each occurrence an integer of 0-3;with the proviso that in the formula at least one q is 2 or 3, or atleast one l is 2 or
 3. 28. The perfluoro(poly)ether group containingsilane compound according to claim 27 wherein l is
 3. 29. Aperfluoro(poly)ether group containing silane compound of formula (1a) orformula (1b):(Rf-PFPE)_(β)-X—(CR^(a) _(k)R^(b) _(l)R^(c) _(m))_(α)  (1a)(R^(c) _(m)R^(b) _(l)R^(a) _(k)C)_(α)—X-PFPE-X—(CR^(a) _(k)R^(b)_(l)R^(c) _(m))_(α)  (1b) wherein: Rf is each independently at eachoccurrence an alkyl group having 1-16 carbon atoms which may besubstituted by one or more fluorine atoms; PFPE is each independently ateach occurrence a group of the formula:—(OC₄F₈)_(a)—(OC₃F₆)_(b)—(OC₂F₄)_(c)—(OCF₂)_(d)— wherein a, b, c and dare each independently an integer of 0-200, the sum of a, b, c and d is1 or more, and the occurrence order of the respective repeating units inparentheses with the subscript α, b, c or d is not limited in theformula; X is a 3-10 valent organic group, α is an integer of 2-9; β isan integer of 1-8; R^(a) is each independently at each occurrence —Z—CR¹_(p)R² _(q)R³ _(r); Z is each independently at each occurrence an oxygenatom, a C₁₋₆ alkylene group, —(CH₂)_(g)—O—(CH₂)_(h)— wherein g is aninteger of 0-6, and h is an integer of 0-6, or -phenylene-(CH₂)_(i)—wherein i is an integer of 0-6; R¹ is each independently at eachoccurrence R^(a′); R^(a′) has the same definition as that of R^(a); inR^(a), the number of C atoms which are straightly linked via the Z groupis up to five; R² is each independently at each occurrence —Y—SiR⁵_(n)R⁶ _(3-n); Y is each independently at each occurrence a C₁₋₆alkylene group or —(CH₂)_(g′)—O—(CH₂)_(h′)— wherein g′ is an integer of0-6, and h′ is an integer of 1-6; R⁵ is each independently at eachoccurrence a hydroxyl group, —OR, —OCOR, —O—N═C(R)₂, —N(R)₂, —NHR, orhalogen wherein R is a substituted or non-substituted alkyl group having1-4 carbon atoms; R⁶ is each independently at each occurrence a hydrogenatom or an alkyl group having 1-20 carbon atoms; n is an integer of 1-3independently per unit —Y—SiR⁵ _(n)R⁶ _(3-n); R³ is each independentlyat each occurrence a hydrogen atom or an alkyl group having 1-20 carbonatoms; p is each independently at each occurrence an integer of 0-3; qis each independently at each occurrence an integer of 0-3; r is eachindependently at each occurrence an integer of 0-3; R^(b) is eachindependently at each occurrence —Y—SiR⁵ _(n)R⁶ _(3-n); R^(c) is eachindependently at each occurrence a hydrogen atom or an alkyl grouphaving 1-20 carbon atoms; k is each independently at each occurrence aninteger of 0-3; l is each independently at each occurrence an integer of0-3; and m is each independently at each occurrence an integer of 0-3;with the proviso that in the formula at least one q is 2 or 3, or atleast one l is 2 or
 3. 30. The perfluoro(poly)ether group containingsilane compound according to claim 29 wherein X is each independently a5-10 valent organic group, α is an integer of 3-8; and β is an integerof 2-7.
 31. The perfluoro(poly)ether group containing silane compoundaccording to claim 29 wherein X is each independently a 5-7 valentorganic group, α is an integer of 3-5; and β is an integer of
 2. 32. Theperfluoro(poly)ether group containing silane compound according to claim1 having an average molecular weight of 2,500-12,000.
 33. Theperfluoro(poly)ether group containing silane compound according to claim27 having an average molecular weight of 2,500-12,000.
 34. Theperfluoro(poly)ether group containing silane compound according to claim29 having an average molecular weight of 2,500-12,000.
 35. Theperfluoro(poly)ether group containing silane compound according to claim27 having an average molecular weight of 2,000-32,000.
 36. Theperfluoro(poly)ether group containing silane compound according to claim29 having an average molecular weight of 2,000-32,000.
 37. Asurface-treating agent comprising at least one perfluoro(poly)ethergroup containing silane compound of the formula (1a) and/or the formula(1b) according to claim
 27. 38. A surface-treating agent comprising atleast one perfluoro(poly)ether group containing silane compound of theformula (1a) and/or the formula (1b) according to claim
 29. 39. Anarticle comprising a base material and a layer which is formed on asurface of the base material from the compound according to claim 27.40. An article comprising a base material and a layer which is formed ona surface of the base material from the compound according to claim 29.41. An article comprising a base material and a layer which is formed ona surface of the base material from the surface-treating agent accordingto claim 6.